The hub of an aircraft proprotor or propeller is typically covered by a spinner. Typically, spinners have an aerodynamic shape that streamlines an aircraft and helps to smoothen the airflow through the blades of the proprotor or propeller and over the surfaces aft of the proprotor or propeller. The blades of a proprotor or propeller may radially protrude from the spinner via cutouts, or holes, in the spinner. The cutouts may allow the blades to flap or move in various directions, including the fore-aft and lead-lag directions, and also allow the blades to pitch at various angles. Current spinner and cutout configurations, however, present a number of drag issues for the aircraft. For example, airflow during forward flight can enter the spinner through the cutouts, thereby creating ram drag. Cutouts may expose large portions of the blade shanks to freestream airflow, further causing ram or profile drag. The exchange of air into and out of the cutouts contributes to the momentum drag experienced by the aircraft. Also, current spinners are shaped such that air pressure is at a maximum near the cutouts, which leads to high air velocity and increased dynamic pressure near the cutouts and a further increase in the aforementioned drag effects. Previous techniques for reducing cutout-induced drag, such as sliding seals, have reliability and maintenance disadvantages and add undue weight, cost and complexity. Accordingly, a need has arisen for spinner and cutout configurations that reduce the various types of drag caused by current spinners while avoiding unnecessary weight, cost and complexity.